ABSTRACT
The belt-pulley model of the wrist has also been incorporated into a sophisticated method for assessing exposures in epidemiological studies of upper extremity cumulative trauma disorders. In contrast to most exposure assessment methods that focus on job
checklists or simple EMG techniques, Moore et al. (1991) used a belt-pulley model to estimate internal mechanical stresses on the extrinsic finger flexor tendons from EMG and electrogoniometer data. The belt-pulley model was used to estimate forces on the tissues surrounding the tendons, tendon excursion, and the frictional work done by the tendons on the surrounding tissues. In a laboratory study of simulated jobs, the frictional work measure was closest to the estimates of risk identified in the cross sectional epidemiological study of cumulative trauma disorders (Silverstein et al., 1986) and carpal tunnel syndrome (Silverstein et al., 1987). More importantly, this model-based exposure assessment system has been used to identify a relationship between exposure to physical risk factors and risk of cumulative trauma disorders (Wells et al., 1992). The modeling approach has also been used to evaluate alternative job rotation systems for cumulative trauma disorder potential (Wells et al., 1995).
